The place I saw ringback defined was in the book by Hall, Hall and McCall of Intel. In that book, page 209 states that ringback is a reflection that goes back toward the threshold. In most treatments of transmission line reflections, a reflection that adds to the incident signal is overshoot and one that subtracts from the incident waveform is undershoot, because it extends under the desired logic level whether the switching waveform is positive going or negative going. The thing called ringback in that book is actually undershoot. > [Original Message] > From: Andrew Ingraham <a.ingraham@xxxxxxxx> > To: <si-list@xxxxxxxxxxxxx> > Date: 5/22/2006 10:02:17 AM > Subject: [SI-LIST] Re: Ring back > > > Ringback is just another name for undershoot. I don't know why someone > > had > > to invent another name for something that already had a name. > > Because ringback is more descriptive, and the correct meaning of undershoot > is so often misunderstood (and mis-defined by certain large semiconductor > companies), perhaps? > > Actually, undershoot includes stepped waveforms (series termination too > large), but ringback usually means the waveform had initially reached (and > probably exceeded) normal levels before swinging back. > > Andy > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu